package com.pmc.dwa.common.utils;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

/**
* JavaScript escape/unescape 编码的 Java 实现
* author QuMao
*/
public class Escape {
	
	private final static String[] hex = {
	"00","01","02","03","04","05","06","07","08","09","0A","0B","0C","0D","0E","0F",
	"10","11","12","13","14","15","16","17","18","19","1A","1B","1C","1D","1E","1F",
	"20","21","22","23","24","25","26","27","28","29","2A","2B","2C","2D","2E","2F",
	"30","31","32","33","34","35","36","37","38","39","3A","3B","3C","3D","3E","3F",
	"40","41","42","43","44","45","46","47","48","49","4A","4B","4C","4D","4E","4F",
	"50","51","52","53","54","55","56","57","58","59","5A","5B","5C","5D","5E","5F",
	"60","61","62","63","64","65","66","67","68","69","6A","6B","6C","6D","6E","6F",
	"70","71","72","73","74","75","76","77","78","79","7A","7B","7C","7D","7E","7F",
	"80","81","82","83","84","85","86","87","88","89","8A","8B","8C","8D","8E","8F",
	"90","91","92","93","94","95","96","97","98","99","9A","9B","9C","9D","9E","9F",
	"A0","A1","A2","A3","A4","A5","A6","A7","A8","A9","AA","AB","AC","AD","AE","AF",
	"B0","B1","B2","B3","B4","B5","B6","B7","B8","B9","BA","BB","BC","BD","BE","BF",
	"C0","C1","C2","C3","C4","C5","C6","C7","C8","C9","CA","CB","CC","CD","CE","CF",
	"D0","D1","D2","D3","D4","D5","D6","D7","D8","D9","DA","DB","DC","DD","DE","DF",
	"E0","E1","E2","E3","E4","E5","E6","E7","E8","E9","EA","EB","EC","ED","EE","EF",
	"F0","F1","F2","F3","F4","F5","F6","F7","F8","F9","FA","FB","FC","FD","FE","FF"
	};
	
	private final static byte[] val = {
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,
	0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F,0x3F
	};
	
	public static String escape(String s) {
		StringBuffer sbuf = new StringBuffer();
		int len = s.length();
		for (int i = 0; i < len; i++) {
			int ch = s.charAt(i);
			if (ch == ' ') {
				// space : map to '+'
				sbuf.append('+');
			} else if ('A' <= ch && ch <= 'Z') {
				// 'A'..'Z' : as it was
				sbuf.append((char)ch);
			} else if ('a' <= ch && ch <= 'z') {
				// 'a'..'z' : as it was
				sbuf.append((char)ch);
			} else if ('0' <= ch && ch <= '9') {
				// '0'..'9' : as it was
				sbuf.append((char)ch);
			} else if (ch == '-' || ch == '_' // unreserved : as it was
				|| ch == '.' || ch == '!'
					|| ch == '~' || ch == '*'
						|| ch == '\'' || ch == '('
							|| ch == ')') {
				sbuf.append((char)ch);
			} else if (ch <= 0x007F) {// other ASCII : map to %XX
				sbuf.append('%');
				sbuf.append(hex[ch]);
			} else {// unicode : map to %uXXXX
				sbuf.append('%');
				sbuf.append('u');
				sbuf.append(hex[(ch >>> 8)]);
				sbuf.append(hex[(0x00FF & ch)]);
			}
		}
		return sbuf.toString();
	}
	
	public static String unescape(String s) {
		StringBuffer sbuf = new StringBuffer();
		int i = 0;
		int len = s.length();
		while (i < len) {
			int ch = s.charAt(i);
			if (ch == '+') {// + : map to ' '
				sbuf.append(' ');
			} else if ('A' <= ch && ch <= 'Z') {// 'A'..'Z' : as it was
				sbuf.append((char)ch);
			} else if ('a' <= ch && ch <= 'z') {// 'a'..'z' : as it was
				sbuf.append((char)ch);
			} else if ('0' <= ch && ch <= '9') {// '0'..'9' : as it was
				sbuf.append((char)ch);
			} else if (ch == '-' || ch == '_' // unreserved : as it was
				|| ch == '.' || ch == '!'
					|| ch == '~' || ch == '*'
						|| ch == '\'' || ch == '('
							|| ch == ')') {
				sbuf.append((char)ch);
			} else if (ch == '%') {
				int cint = 0;
				if ('u' != s.charAt(i+1)) {// %XX : map to ascii(XX)
					cint = (cint << 4) | val[s.charAt(i+1)];
					cint = (cint << 4) | val[s.charAt(i+2)];
					i+=2;
				} else {// %uXXXX : map to unicode(XXXX)
					cint = (cint << 4) | val[s.charAt(i+2)];
					cint = (cint << 4) | val[s.charAt(i+3)];
					cint = (cint << 4) | val[s.charAt(i+4)];
					cint = (cint << 4) | val[s.charAt(i+5)];
					i+=5;
				}
				sbuf.append((char)cint);
			}
			i++;
		}
		return sbuf.toString();
	}
	
	public static void main(String[] args) throws UnsupportedEncodingException {
		String stest = "中文1234 abcd[]()<+>,.~\\";
		System.out.println(stest);
		System.out.println(escape(stest));
		System.out.println(URLEncoder.encode(stest,"utf-8"));
		System.out.println(unescape(escape(stest)));
	}
}
